The majority of the playerbase that will be 90 and have that good of gear for the first week or more of LFR are going to be the players that don't need or at least the content was not designed for. It will be all of the normal and hardmode raiding guilds that have continuous heroic runs.
The JP gear is iLevel 450 with no iLevel 463 available via vendor. So seriously WTF? I understand needing to have a high iLevel for the LFR to be successful but 463 is putting the bar a little high.
With Dragon Soul the requirement was 372-373 with the heroics dropping iLevel 378 gear and JP gear was set at 378. So I think either the JP gear needs to have the iLevel increased to 463 like heroic dungeon gear or the LFR iLevel requirement drastically dropped. 457 would be a good middle ground.